Rational design and regulation of tremella-like selenium-doped MoS₂ for highly reversible sodium storage

Abstract

Molybdenum disulfide (MoS2), due to its high theoretical specific capacity (670 mAh g-1), has evoked considerable investigation interest regarding Na+ storage. Nonetheless, the irreversible conversion of original material MoS2 into...

S-doped C@MoSe2(1-x)S2x@MWCNT heterostructure as high-rate and long-cycle stability anodes for Na+ batteries

“…11c display the out-of-plane (A1g) (238 cm -1 ) and in-plane (E 2g 1 ) (283 cm -1 ) vibrational modes of Mo-Se. There is no obvious detection of signals of Mo-S out-of-plane (A1g) and in-plane (E 2g 1 ) at ~400 cm -1 , reflecting that the amount of doped S in the system is low [7]. It was observed that the strength ratio of (A1g) to (E 2g 1 ) in C@MoSe2(12.26)、 C@MoSe2(1-x)S2x@MWCNT (14.31) and PEG-200-2-C@MoSe2(1-x)S2x@MWCNT (13.82) are rather close, which confirms that the coating of carbon on MoSe2(1-x)S2x@MWCNT does not adversely affect the layered structure of the three samples [7,33].…”

“…After the second cycle, the peak at 1.4 V (discharging) is related to the conversion of MoSe2(1-x)S2x to Mo and Na2Se (Na2S). Peaks at 1.69 V (charging) is related to the conversion of Na2Se (Na2S) to Se (S), and oxidation of Mo (MoSe2(1-x)S2x) [7,27].…”

“…Theoretically, MoSe2 has electrochemical properties like that of MoS2, and can be used as anode material for SIB [30][31][32][33][34][35][36][37][38]. Because the relatively high conductivity (10 −4 S m −1 ) and large radius (1.6 Å) of selenium (Se), doping Se into MoS2 lattice to form S2−xSex interlayer will increase conductivity and expand interlayer spacing, thereby enhancing Na + storage capacity [7,21,[30][31][32]. For example, Liu et al constructed MoSSeNSs@NC/hC-NC for SIB, and due to the partial replacement of sulfur (S) by Se, the MoSSe delivered higher SIB storage capacity [30].…”

Boosted Hydrogen Evolution via Molten Salt Synthesis of Vacancy-Rich MoSxSe2–x Electrocatalysts

“…Nonetheless, the high-temperature synthesis often damages the defect sites that are crucial for catalytic activity, leading to suboptimal performance. While the solvothermal method can produce MoS x Se 2– x with a high density of defects at relatively lower temperatures, enhancing its HER activity, the process involves hazardous steps and the use of toxic Se compounds, which hinders its industrial feasibility. − To date, developing a simple and scalable synthesis method for defective MoS x Se 2– x , suitable for mass production and broad application, remains a significant challenge.…”

A cobalt-doped hollow ZnS polyhedra@porous carbon shell composite anode for high-rate sodium-ion batteries

“…1–4 To date, various TMSs ( e.g. , CoS 2 , 5,6 ZnS, 7,8 Ni 3 S 2 , 9 NiS 2 , 10,11 and MoS 2 12,13 ) have been extensively researched as next-generation anodes of sodium-ion batteries (SIBs). Among them, nontoxic ZnS attracts a lot of attention due to its low working potential (<1.0 V, vs. Na/Na + ) and relatively high theoretical capacity (about 581.4 mA h g −1 ).…”